The present invention relates generally to an industrial robot adapted to be used in association with a machine tool, and more particularly to a robot hand of an industrial robot, which hand is provided with means for removing chips or other foreign materials attached to a workpiece holder of a machine tool or workpiece, per se.
Generally, the industrial robot is employed as an industrial manipulating device used in association with diverse kinds of machines and apparatuses for the purpose of automatically transferring an article to and from the machines and the apparatuses. The automatic manipulating operation of the industrial robot is always controlled by a robot controller to which the instruction data for the robot operation are preliminarily given. When the industrial robot is used in association with an automatic machine tool, such as a numerically controlled machine tool, the industrial robot is employed for the automatic transferring of a workpiece between a given workpiece station and the machine tool and for attaching the workpiece to and detaching the workpiece from a chucking device of the machine tool or a holding jig of the machine tool. The employment of the industrial robot can highly contribute to promoting the efficiency of the operation of the automatic machine tool. At this stage, it should be understood that when a workpiece is attached to the chuck device or the holding jig by the industrial robot, all chips and other foreign materials attached to the chucking device or the holding device, the workpiece, and the robot hand should be removed in order that the workpiece is rigidly and accurately held by the chucking device or the holding jig. That is, the cleaning of the chucking device or the holding jig of the machine tool, as well as the cleaning of the workpiece and the robot hand, are indispensable for the accurate and rigid holding of the workpiece by the chucking device or the holding jig. For this reason, conventional machine tools are provided with a cleaning means which uses pressurized air or a cooling liquid as a cleaning agent for removing chips and other foreign materials attached to the chucking device or the holding jig. When the cleaning operation is carried out, the robot hand of the industrial robot must be moved away from the chucking device or the holding jig, since the cleaning agent is blown by the cleaning means toward the chucking device or the holding jig so that the chips are blown free of the chucking device or the holding jig. Otherwise, the blown chips might become attached to the robot hand. After the cleaning operation of the machine tool, the robot hand must again be brought close to the chucking device or the holding device. Accordingly, the efficiency of the industrial robot is rather low. Particularly in the case where the industrial robot is provided with a particular robot hand having two sets of graspers for the purpose of shortening the time required for attaching a workpiece to and detaching a workpiece from the machine tool, the above-mentioned low efficiency of the industrial robot is quite disadvantageous.